Clinton is not running for president in 2020, but told News 12 in New York earlier this year that "I'm going to keep on working and speaking and standing up for what I believe."

With more than seven months to go before the Iowa caucuses, Biden has led virtually every poll of the Democratic presidential field. But the former vice president has had a bumpy past few weeks, highlighted by the criticism he received after reminiscing about his relationship with segregationists he worked with in the Senate decades ago.

Trump spoke at length about his 2016 race during the "Meet the Press" interview, saying he outworked Clinton in the swing states of Michigan, Wisconsin and Pennsylvania, which helped him win the White House.

He also downplayed losing the popular vote by almost 3 million votes by arguing he didn't campaign in highly populated states like California and New York. And he again raised unfounded claims that "illegal voting" had aided Clinton in winning the popular vote.

The president also made clear that he wants his 2016 running mate, Vice President Mike Pence, to reprise his role during the 2020 campaign. When asked whether Pence would be on the ticket, Trump replied "100 percent, yes," praising Pence as a "terrific vice president" and "my friend."

Trump recently demurred when asked in an interview on Fox News to endorse Pence to succeed him, but the president told NBC he only hesitated because that election is "so far out."

"That would be the only reason. Now, what happens in 2024? I don't know that Mike is going to run. I don't know who's running or anything else," he said.

And while the president sometimes makes references to staying in office for more than two terms, he said those comments are only a "joke."